1. Field of the Invention
This invention relates to an image reading apparatus for reading image information recorded on a film such as a microfilm.
2. Description of the Related Art
For the purpose of enabling image information photographed on a film such as a microfilm to be reproduced on a recording paper, a system which reads out the image information with a line sensor provided with CCD elements, converts the image information into electronic information, forwards the signal of electronic information to a printer, and prints the image on the recording paper has been available. This system has the advantage that clusters of image imformation read out by a plurality of image reading apparatuses can be printed by shared use of one printer. Each image reading apparatus incorporated in this system is provided with a memory part capable of provisionally storing the signal from the CCD elements. The image information stored in the memory part is sequentially transmitted to the printer. The line sensor provided with the CCD elements comes in two types, the type called a contact CCD sensor having a size equaling the width of the recording paper on which the image information is to be reproduced, namely the length corresponding to the size of the recording paper in the main scanning direction and the type called a reduced CCD sensor having CCD elements arranged in a high density and having a length smaller than the width of the recording paper to be used for the reproduction of the image information.
In recent years, the desirability of developing a system which enables information recorded on a film such as a 35-mm film to be reproduced on a relatively large recording paper of the A2 or A1 size has been finding growing recognition. When an image is to be reproduced on such a large recording paper as mentioned above at a resolution of 400 dpi (dots per inch), the reading speed is slow and the operational efficiency is inferior no matter whichever of the reduced and contact type of CCD sensor may be adopted. The signals from the multiplicity of CCD elements of which one sensor is formed are destined to be transmitted to the memory part. The memory part thus used, therefore, is required to have a large capacity. As a result, the cost for the production of the sensor is high and the large volume of image data from the sensor must be processed within the memory part. The reading speed is proportionately slow and the reproduction of an image on the recording paper of a large size is obtained only with difficulty.
When image information is to be printed on the recording paper of a large size, the recording paper on which the printing has been completed is subjected to the work of automatic folding by the use of a paper folding device. On account of the procedure involved in the paper folding device, it possibly becomes necessary for the film having pertinent information recorded thereon to be rotated so that the image to be reproduced on the recording paper during the process of printing will be directed as required. There are times when such additional information as a date is printed in one of the four corners of the recording paper at the same time that the image information is printed on the recording paper. When the part for printing the additional information is set apart only on one side in the direction of width of the recording paper, the printing of the information is obtained on one terminal side of the recording paper.
For the elimination of this disadvantage, the alteration of the output of printing in any desired direction is accomplished by the practice of optically reading image information recorded on the film by means of a sensor and committing the resultant image signals wholly to an image memory and processing these signals therein. When this method is relied on to effect the alteration of the direction of the output of printing mentioned above, the processing of the image requires use of a memory. Thus, the cost of production of the apparatus is proportionately increased and the processing itself is suffered to consume time. The printing, therefore, cannot be performed quickly and the apparatus cannot be operated efficiently.